CODEWITHSUNDEEP
javascriptimage
Stephen Westland
Stephen Westland

Reputation: 23

simple maths with image data in javascript

I am trying to understand how to do some basic operations on image data in javascript. In the following code snippet I have some data, called imgData, and when I send imgData.length to the console I get 1032000 which is correct. The image is 600x430 and 600x430x4=1032000. However, I am trying to sum the R values. When I do this I get 20 which can't possibly be right. Is this something to do with the fact that the image data are uint8 type?

  imgData = ctx.getImageData(0, 0, srcImage.width, srcImage.height);
  var i;
  var sumR;
  sumR = 0;
  console.log(imgData.data.length);
  for (i = 0; i < imgData.data.length; i += 4) {
    sumR = sumR = imgData.data[i];
  }
  console.log(sumR);

Upvotes: 0

Views: 121

Answers (1)

GirkovArpa
GirkovArpa

Reputation: 4912

As trincot helpfully pointed out, the issue was a typo: + instead of =.

Upvotes: 1

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